1. Technical Field
The present invention relates to a composite of consolidation-hardening pile for soft ground and, more particularly, a composite of consolidation-hardening pile for the soft ground, which is not only used in C.I.P. (Cast In place Pile) method using a cast-in-situ pile, but also in Chemical Pile method for making a pile by filling a quicklime (calcium oxide) in a hall to increase strength of the ground, and to prevent the ground from being sunken.
2. Background Art
Generally, there are various methods of construction to make the soft ground better. One of methods is a Chemical Pile method.
In addition, the C.I.P. method is one of the methods, which is used in a deep foundations construction.
Brief description of the methods is as follows.
A vertical pile is formed by first making a hall of 20–40 cm diameter in the soft ground and then, filling calcium oxide in the hall. The quicklime(calcium oxide) in the pile reacts with the moisture in the ground due to its chemical characteristic to originate an exothermic reaction of about 300° C., an absorption reaction[CaO+H2O→Ca(OH)2], swelling effect, and ion exchange reaction. Thus, the amount of the moisture in the ground is reduced, and the pile acts as a consolidation in the horizontal direction is occurred by the swelling.
Therefore, a strength of the ground is increased, and sinking of the ground is prevented.
As the pile made by only the quicklime, however, has the strength of 5 kg/cm2, it is inappropriate as a supporting pile. Further, there are problems that working safety is impeded by a rapid exothermic reaction, and an expensive exclusive apparatus should be used.
The C.I.P.(Cast In place Pile) method is a kind of a cast-in-situ concrete pile. The file is formed by first drilling the ground by means of an Earth Auger, and then, filling a coarse aggregate and a cement paste in the formed hall.
At this time, the diameter of pile is over 25 cm at the least, and is 30 cm, 45 cm, 60 cm or 90 cm.
The C.I.P. method is applied to the sediment-based ground by using a casing pipe, but not applied to the soft ground. Therefore, a ground improving effect is hardly produced.